In fact, during the first few seconds after he jumps from his capsule above 120,000 feet, he won’t even feel like he’s falling. Air resistance will be so minimal that it will seem like he’s simply floating above Earth. As he gains speed and hits denser atmosphere, wind blast forces will kick in and Baumgartner will be on his home skydiving turf, pulling the chute at around 5,000 feet, where there’s enough air for it to fully deploy. By then, it will feel much like a typical skydive, except it will have lasted longer and the view will have been better.

In may 1966, Three months after his failed second try, Nick Piantanida took one more shot at breaking Kittinger’s record. The oxygen hose disconnection problem had been resolved, and he considered the third attempt to be a shoe-in. On May 1, he lounged near his gondola awaiting takeoff, then kissed his wife before closing his helmet visor and sealing his suit. He climbed into the gondola while the balloon filled, then took off. Things went smoothly until he reached around 57,000 feet. At that point, roughly an hour into his flight, Piantanida’s team heard a whooshing sound over the radio. They asked him to respond, but he could only get out part of the word “emergency.”

By the time the team got him back on the ground, Piantanida had suffered massive tissue damage due to ebullism, and he was barely conscious. At the hospital he slipped into a coma. Four months later, he died. According to Ryan, all evidence points not to an equipment failure, but to a human one.

“Piantanida’s flaw was his refusal to set up an organizational structure, to have anybody there who had the power to tell him ‘You can’t go,’ ” says Ryan. Kittinger, who refused to join Piantanida’s team for that reason, though he had been asked several times, says that Piantanida wouldn’t have died if he’d had a Jon Clark on his team. Clark would have seen him walking around without his helmet sealed only minutes before takeoff, and would have aborted the flight then and there, since Piantanida was supposed to be breathing pure oxygen for at least an hour before the flight to prevent decompression sickness.

That breach in protocol wasn’t what killed him, though. Piantanida had a bad habit of opening his helmet visor, and the evidence suggests that he did this at 57,000 feet, perhaps to clear condensation, and couldn’t get the visor closed again. It was a mistake he had been warned about many times.

There have been a few would-be record setters since then, but none has come close to getting off the ground. Ryan says that none of them has had Red Bull’s money, or the expertise and discipline of Kittinger, Clark, and the rest of the Stratos team.

“Not all of us can or even want to do this stuff,” Ryan says. “I think that’s why we all sit here and watch, holding our breath, hoping these guys make it.”

That’s another thing that has changed since the 1960s. Baumgartner’s leap will be captured by nine high-definition cameras, including three strapped to his body. Whatever happens, we’ll all be able to watch, holding our breath, as it’s webcast live.